This section provides background information related to the present disclosure which is not necessarily prior art.
Equipment control systems may include touchless object detections systems that determine the proximity of an object and control equipment based on the proximity. For example, a dispensing machine, such as a beverage or ice dispensing machine, may include a touchless object detection system that determines the proximity of a container to a dispensing apparatus. When the container is in close proximity to the dispensing apparatus, the dispensing machine may initiate dispensing into the container.
Such a touchless object detection system may include an infrared (IR) emitter and an IR receiver. For example, the IR emitter may emit pulses of IR light that reflect off of the object, such as the container, and back to the IR receiver. The touchless detection system may measure an intensity of the reflected IR pulses and determine the proximity of the object based on the measured intensity of the reflected light. For example, the measured intensity of the reflected light is generally greater for an object that is closer than it is for an object that is farther away, provided the two objects have the same or similar color and/or level of transparency. The intensity of the reflected light is dependent, however, on the color and/or transparency of the object in addition to the distance of the object to the sensor. For example, the intensity of light reflected off of a relatively transparent object, such as a transparent container, is generally less than the intensity of light reflected off of an opaque object, such as an opaque container, at the same distance from the sensor. For this reason, object detection systems that determine proximity based on the measured intensity of light reflected off of the object can have difficulty accurately determining the proximity of objects of different colors and levels of transparency.
Touchless object detection systems may also utilize ultra-sonic distance sensors to determine the presence of an object. Such systems, however, often have a minimum detection range that is greater than the desired object proximity for a particular system, such as a beverage or ice dispensing system. As such, object detection systems utilizing ultra-sonic distance sensors may not be suitable for detection of objects in close proximity to the sensor.